USED TO DETERMINE CORRECT TUBING OR STOPPER SIZE NEEDEDThe handy Stopper / Tubing Sizer easily determines the correct size of the cork or stopper needed for any flask, bottle, etc. Two scales are provided: one for rubber and vinyl stoppers and the other for corks. The backside is a circular scale to size tubing outside diameters between 4 and 52mm. 156mm x 66mm wide (6 1/8"x 2 5/8") at the top.